''Spy vs Spy''

Some transcripts from ''Venona'', a U.S. counter-intelligence program that lasted from 1943 to 1980 to decrypt messages sent by Soviet intelligence.

Venona program documents (N.S.A. , published 1995)

https://archive.org/stream/foia_Venona-HQ-1/Venona-HQ-1#page/n65/mode/2up